Electrical equipment such as engines, construction machines, marine vessels, and robotically controlled devices often operate in hazardous environments. In order to ensure proper and safe operation within these environments, strict regulation on the manufacture of this equipment has been instituted. For example, when operating in a volatile environment filled with combustible fumes, the electrical equipment must be designed to minimize the likelihood of arcing that could ignite the fumes. In fact, the electrical equipment must be designed such that, even if the equipment is impacted or subject to tensile stresses, the likelihood of arcing is still minimized and continued operation of the equipment is ensured. In order to comply with these regulations, equipment manufacturers have concentrated heavily on improving the robustness of wiring harnesses utilized to transmit power and control signals to, from, and within the equipment.
One example of a robust wiring harness designed to improve environmental protection and provide strain relief to soldered joints within the harness is disclosed in U.S. Pat. No. 6,439,929 (the '929 patent) issued to Jenets on Aug. 27, 2002. Specifically, the '929 patent discloses a wiring harness having a backshell for soldered connection of a wire to a mating receptacle of an electronic device. A conductive tubular braided shield is disposed over the wire and one end of the backshell. The braided shield may connect to the backshell in one of two ways. The first way includes extending the tubular braided shield over a rim of the backshell and then holding the braided shield in place on the rim with a clamp. Alternatively, in situations where the rim is omitted from the backshell, a shrink tube may be utilized to hold the braided shield on the end of the backshell. The backshell may provide both impact resistance for the wires contained therein, as well as reduce some of the stress applied to the wires in a tensile situation.
Although the wiring harness of the '929 patent may have improved robustness, it may still be inadequate for some situations. In particular, if only one end of the wiring harness is rigidly connected to a backshell, the braided shield has a taut length greater than that of the wires, or the braided shield is allowed to deform an amount greater than the wires contained therein, excessive strains within the wires may still be possible. In addition, because the shrink tube of the alternative embodiment connects only the braided shield to the backshell, extensive tensile strains may still be induced within the wire. And, because the shrink tube terminates at the end of the backshell, the environmental protection and strain relief provided by the shrink tube may be minimal.
The wiring harness of the present disclosure solves one or more of the problems set forth above.